The aim of the research program is to understand the basic brain mechanisms which govern fundamental adaptive behaviors of animals, and th present focus is to study how the medial hypothalamus participates in body energy balance regulation. Specifically, our working model, based on completed work, is that the medial hypothalamus is crucial to body energy regulation by its elaboration of both excitatory and inhibitory control of feeding in response to body nutrient depletion and repletion. The present grant year is devoted to a continuing analysis of how medial hypothalamic damage changes animals' regulatory responsivity to major nutritional challenges administered in the context of its ongoing feeding cycle. Using autoradiography procedures we are also analyzing the disperison of C14 labeled nutrients in diencephalic areas of the brain. Further, we are determining whether the linkage between energy intake and neural regulation of feeding might be achieved through the generation of neuroactive amino acids (GABA, glycine, glutamic acid) from intermediate carbohydrate metabolism, and whether these processes might be connected to longer-term lipid and glycogen pools within the medial hypothalamus.